The present invention relates to a remote control device for remotely controlling an electric appliance or the like by using infrared rays or the like, and particularly relates to a learning remote control device in which a remote control signal from another remote control device for an electric appliance or the like is recorded so that the learning remote control device can remotely control a plurality of electric appliances by itself.
The operation mode of an appliance such as a television set, a video cassette recorder and an audio machine can be shifted by a remote control, device employing infrared rays or the like. Besides, there is a learning remote control device in which a remote control signal from a remote control device is recorded so that the learning remote control device can remotely control a plurality of appliances by itself.
FIG. 4(a) shows a remote control signal which is used by a non-learning remote control device, while FIG. 4(b) shows signal data which are stored by a conventional learning remote control device. The non-learning remote control device transmits the remote control signal which is intermittent as shown in FIG. 4(a. A remotely controlled appliance detects the pattern of the remote control signal to find out a preset code to perform an action corresponding to the preset code. The times t.sub.1, t.sub.3, . . . and t.sub.9 during which the level of the remote control signal transmitted by the non-learning remote control device is nonzero, and the other times t.sub.2, t.sub.4, . . . and t.sub.10 during which the level of the remote control signal is zero are measured by the timer of the learning remote control device or through software control or the like so that a combination of the data of the measured times shown in FIG. 4(b) is stored in a portion of a memory, which corresponds to a control key manipulated selectively beforehand or to the like. When the control key is manipulated afterwards, the combination of the data stored in the portion of the memory, which corresponds to the control key, is read from the portion of the memory and the widths of pulses transmitted on the basis of the combination of the data are regulated so that the remote control signal is reproduced and transmitted.
FIG. 3 shows a block diagram of the conventional learning remote control device comprising a receiving section 11 which receives the remote control signal transmitted from the non-learning remote control device through the use of infrared rays or the like and performs the infrared/electric conversion of the received remote control signal; a control section 12 which processes the data of the remote control signal received by the receiving section; the memory 13 for storing the data of the received remote control signal; a plurality of control keys 14, each of which is manipulated to store the data of a remote control signal or to select stored data to transmit a reproduced remote control signal; a switch 15 for shifting the operation mode of the learning remote control device to store the data of the remote control signal or transmit the reproduced remote control signal; a display section 16 for indicating the sequence of the operation of the learning remote control device, a manipulating instruction or the like to the user of the device; and a transmitting section 17 which performs the electric/infrared conversion of the stored data selected by the control key, to reproduce the remote control signal, and transmits the reproduced remote control signal.
When the remote control signal is transmitted by manipulating the non-learning remote control device, the remote control signal is received and demodulated by the receiving section 11 of the learning remote control device so that the time data of the signal are obtained. The combination of the time data of the remote control signal is written in the reception buffer of the memory 13 by the control section 12. When the writing of the combination of the time data of the remote control signal in the reception buffer is completed, the display section 16 makes an indication to urge the user to re-manipulate the same control key of the non-learning remote control device. When the same control key is re-manipulated so that the remote control signal is transmitted from the non-learning remote control device, the signal is received and demodulated by the receiving section 11 again so that the combination of the time data of the signal is obtained again and compared in the control section 12 with that previously written in the reception buffer. If the mutually compared combinations of the time data are coincident with each other, the combination is written in a storage region of the memory 13, which corresponds to the same control key 14. This process of transmitting the same remote control signal twice ensures that the remote control signal has been properly received and demodulated. The same number of remote control signals as the control key 14 can thus be recorded to remotely control the appliance by the learning remote control device.
When a desired control key 14 is manipulated as the operation mode of the learning remote control device is shifted for transmission, the data are read from the storage region of the memory 13, which corresponds to the manipulated control key, and the remote control signal corresponding to the read data is reproduced and transmitted by the transmitting section 17, so that the appliance is remotely controlled by the learning remote control device in the same manner as it is remotely controlled by the non-learning remote control device.
There are remote control signals each having a prefix furnished in consideration of the future extension of the code of the signal, the adjustment of input level of a light receiving portion or the like. The prefix is furnished at a code which is for changing the channel of a television set, the operation mode of an amplifier or a video cassette recorder or the like. Not only the prefix of the remote control signal, which acts so as to sequentially change the status of an appliance when a single key is continually manipulated, but also that of the other remote control signal, which acts so as not to sequentially change the status of the appliance when the single key is continually manipulated, are sequentially altered along with the continual manipulation of the single key. For example, cyclic remote control signals, in which prefixes a, b, c and d which differ from each other for the various operation modes of a control amplifier or the like are added in front of codes x which are for stepwise changing the use of a tuner, a player, a compact disk and an auxiliary unit in cyclic order by sequentially manipulating a single key of a remote control device, as shown in FIG. 2, are sequentially transmitted along with the sequential manipulation of the single key. Since the prefixes of the cyclic remote control signals vary as the single key is sequentially manipulated, the data of the cyclic remote control signal transmitted by manipulating the key firstly and received by the conventional learning remote control device do not coincide with those of the other cyclic remote control signal transmitted by manipulating the key secondly and received by the conventional learning remote control device. For that reason, there is a problem that the conventional learning remote control device cannot store the data of the cyclic remote control signals.